Dye developer diffusion transfer system and yellow dye developer therefor



United States Patent 3,502,469 DYE DEVELOPER DIFFUSION TRANSFER SYSTEM AND YELLOW DYE DEVELOPER THEREFOR Walter M. Bush, Victor, and Derek D. Chapman and Richard W. Becker, Rochester, N.Y., assignors to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey No Drawing. Filed Dec. 29, 1967, Ser. No. 694,397 Int. Cl. G03c 5/54, 1/40 US. Cl. 96-29 12 Claims ABSTRACT OF THE DISCLOSURE A yellow hydroquinone dye developing agent having a lower alkoxy group substituted on the 5-position of the hydroquinone nucleus is provided for dye developer diffusion transfer systems. Precursors for such dye developers are produced by reacting a lower aliphatic alcohol with a quinone in the presence of zinc chloride. Novel photosensitive materials containing the dye-developers are provided.

This invention relates to the art of photography and more particularly to a multicolor diffusion transfer process in photography and materials adapted to use in the process.

A diffusion transfer color process has been described in a number of patents, including British Patent 804,971, published Nov. 26, 1958, wherein photographic elements containing silver halide emulsion layers and layers containing difiFusible dye developers (dyes having a silver halide developing function) are exposed to record the latent image in the silver halide and then treated with an alkaline processing composition which permeates the emulsion layer and layers containing the dye developers which then develop the latent images to silver images. At the same time oxidation products of the dye developers are formed in situ with the silver images and which are relatively nondiffusing in the colloid vehicle of the layers.

The nondiffusing character of the oxidized dye developers is apparently due at least in part to a decrease in solubility in the alkaline processing liquid, and may also be due to a hardening effect of the oxidized developer upon the colloid vehicles of the layers which retards the diffusion of the oxidized dye developers. The residual unoxidized dye developers remaining in the layers in image- Wise distribution are transferred by diffusion to a superposed reception element substantially to the exclusion of the silver image and oxidized dye developer to provide a positive dye image.

When an element containing differentially sensitized silver halide emulsion layers is used and subtractively colored dye developers are present in or contiguous to the respective emulsion layers, upon treatment with the processing liquid the dye developers are oxidized and rendered nondifr'using in the developed regions of the layers and the residual dye developer images in the positive regions are transferred by diffusion and in register to the reception element to provide a multicolor reproduction.

In a typical process for producing the dye developer images a sensitive element comprising a plurality of silver halide emulsion layers differentially light-sensitive (sensitive to different regions of the spectrum), having contiguous dye developers which may be subtractively colored with respect to the sensitivity of the corresponding emulsion layer is exposed to a colored subject and processed by wetting with an alkaline processing solution such as one containing hydroxyethyl cellulose as a thickening agent, in contact with the reception layer. The exposed silver halide in the emulsion layers is developed and 3,502,469 Patented Mar. 24, 1970 renders the dye developers nondiffusing in the regions of development, allowing the dye developers in the undeveloped regions to transfer imagewise by diffusion and in register to the reception layer to yield a multicolor dye developer image thereon.

The sensitive element may contain superposed gelatin emulsion layers sensitized to the red, green and blue regions of the spectrum. Under each emulsion layer is a light-intensitive gelatin layer containing a subtractively colored dye developer, i.e., a cyan, magenta or yellow colored dye developer. Gelatin interlayers separate the middle emulsion layer and its underlying layer of dye developer from the other two emulsion layers and dye developer layers.

Yellow dye developers, such as 1-phenyl-3-N-n-butyl carboxamido 4-[p-(2,5'-dihydroxyphenethyl) phenylazo] -5-pyrazolone have been successfully employed in multicolor dye diffusion transfer systems. However, attempts to improve upon the photosensitive properties such as film speed and the like, of photosensitive elements containing such dye developers have proven difiicult.

It is an object of this invention to provide a novel dye developers diffusion transfer system.

It is another object of this invention to provide a novel dye developing agent.

It is still another object of this invention to provide a method for the production of such novel dye developmg agents.

It is still a further object of this invention to provide photosensitive elements which contain dye developers and have improved photosensitive properties.

These and other objects of the invention are accomplished by providing a 5-[lower] alkoxyhydroquinone substituted on the 2-position by a yellow image-producing chromophore moiety, which compounds are suitable for utilization as a yellow dye developing agent.

It has been found that photosensitive elements suitable for use in dye diffusion transfer systems and having unexpected increases in photographic speed are provided by incorporating therein a yellow dye developer that contains a lower alkoxy group on the 5-position of the hydroquinolyl radical. The dye developers of this invention have primary absorption from the near violet (about 390 nm.) to radiation of about 500 nm., as is characteristic of yellow dyes.

The dye developers of the present invention may be represented by the following structural formula:

wherein R represents a lower alkyl group, such as methyl, ethyl, propyl and butyl, and X represents a yellow-imageproducing chromophore moiety.

The term yellow image-producing chromophore moiety" as employed herein is intended to include a moiety which when taken in conjunction with the lower alkoxysubstituted hyroquinolyl moiety will form a yellow transfer image upon the receiving element when processed in an alkaline solution.

According to a preferred embodiment of the invention, X may be represented by the group -R Ar-N=NQ )m wherein R represents an alkylene group of from 1 to carbon atoms (e.g., methylene, ethylene, trimethylene, butylene, etc.); Ar represents an aryl group of the benzene or naphthalene series (e.g., phenyl, tolyl, xylyl, naphthyl, etc.); Z represents either a lower alkyl of from 1 to 5 carbon atoms (e.g., methyl, ethyl, n-propyl, isobutyl or n-pentyl) lower alkoxy of from 1 to 5 carbon atoms (e.g., methoxy, ethoxy, n-propoxy, isobutoxy, or n-pentoxy) or a halogen (e.g., Cl, Br, F or I); m represents 0, 1 or 2; and, Q represents a S-pyrazolone group attached, at the 4-carbon atom thereof, to the azo group. The S-pyrazolone group can contain various substituents, such as an aryl group (e.g., phenyl or naphthyl) in the 1- position and, in the 3-position, an amino group, an N- alkylcarboxamido group (wherein the alkyl group has from 1 to 12 carbon atoms, e.g., methyl, butyl, hexyl, heptyl, 3-ethylhexyl, decyl or dodecyl), or an N-cyclohexylcarboxamido group. Preferred dye developers include: 4- [p-( 2,5 '-dihydroxy-4'-methoxyphenethyl phenylazo] l-phenyl-3-N-n-hexylcarboxamido5-pyrazolone; 4-[p-(2',5-dihydroxy-4'-ethoxyphenethyl)phenylazo]-1- phenyl-3-N-n-hexylcarboxamido-S-pyrazolone; 4- [p- 2,5 '-dihydroxy-4-propoxyphenethyl) phenylazo] 1-phenyl-3-N-n-hexylcarboxamido-5-pyrazolone; 4-[p-(2,5-dihydroxy-4-butoxyphenethyl)phenylazo]-1- phenyl-3-N-n-hexylcarboxamido-5-pyrazolone; 4- [p- 2',5 -dihydroxy-4'-methoxyphenethyl) phenylazo l-phenyl-3-carbethoxy-5-pyrazolone; 4- [p-(2',5'-dihydroxy-4-ethoxyphenethyl) phenylazo] -1- phenyl-3-carbethoxy-5-pyrazolone; 4-[p-(2,5'-dihydroxy-4'-propoxyphenethyl)phenylazo]- 1-phenyl-3-carbethoxy-5-pyrazolone; 4- [p- (2',5'-dihydroxy-4-butoxyphenethyl)phenylazo] -1- phenyl-3-carbethoxy-5-pyrazolone; 4- [2-chloro-p- 2',5 -dihydroxy-4'-methoxyphenethyl phenylazo] -1-phenyl-3-carbethoxy-5-pyrazolone The novel dye developers of the present invention are produced from precursors that are produced by reacting a quinone, that is substituted in the 2-position, with a lower aliphatic alcohol in the presence of zinc chloride. The production of the dye developer precursor may be represented by the following equation:

II N W" W" K/ ZIICIZ H H O O OH:

0 ll fiomom-Qnme 0 CH: OHsOH l k/ Zn C12 Wwmcm-Qmnoo on,

CHzO

The maximum theoretical yield of the 5-methoxy hydroquinone is 50 percent and in practice the yield is less than 20 percent. However, the yield can be improved by the addition of silver oxide to the reaction mixture after the isolation of the 5-methoxy quinone. In this manner, the hydroquinone byproduct is converted back to the original quinone reactant, which can then undergo further methanol addition and oxidation to yield more of the 5-methoxy quinone dye developer precursor. This utilization of the byproduct quinone improves the yield to about 25 percent.

The 5-(lower) alkoxy dye developers of the present invention may be advantageously provided in a multilayer, multicolor photosensitive element in conjunction with other suitable dye developers, e.g., cyan and magenta dye developing agents. Such dye developers are well known in the photographic art. These compounds likewise function both as a. silver halide developing agent and as a dye in photographic difiusion transfer systems.

Typical useful cyan and magenta dye developers are described in columns 9-13 of US. Patent 3,146,102, as well as elsewhere in the patent literature, including: Australian 220,279; German 1,036,640; British 804,971 and 804,973-5; Belgian 554,935; French 1,168,292; and Canadian 577,021 and 479,038.

The yellow dye developers of the present invention, as well as the cyan and magenta dye developers referred to above are characterized as being relatively nondiffusible in colloid layers such as the hydrophilic organic colloids used in photographic emulsions at neutral pH, but diffusible in the photographic elements in the presence of alkaline processing solutions. Generally, the dye developers are substantially insoluble in water, which property necessitates the use of organic solvents to incorporate the dye developers into the organic colloid layers of the photoelement.

In the photographic elements of the invention, the dye developers are preferably incorporated in hydrophilic organic colloidal vehicles or carriers, which comprise the layers of the photographic element, while being dissolved in high-boiling or crystalloidal solvents and dispersed in finely-divided droplets. Typical high-boiling, waterinsoluble solvents that may be used to dissolve the dye developers in preparing the dispersions are described on page 2, col. 2 and page 3, col. 1 of US. Patent 2,322,027.

The dye developers utilized in the photographic elements may also be incorporated into vehicles soluble in organic solvents which are also solvents for the dye developers. Likewise, other incorporating techniques for the dye developers such as ball-milling may be utilized.

The dye developers are utilized contiguous to the silver halide of the photographic silver halide emulsion layers of the present photographic elements. The dye developers may be incorporated directly in the silver halide emulsions or preferably positioned in a sublayer contiguous to each silver halide emulsion layer. The contiguity of the dye developer with respect to the silver halide may take the form of a mixed packet system wherein the dye developer may be present in a matrix surrounding a particle or globule containing silver halide grains. The dye developers are preferably substantially complementary in color to the color of the light recorded or spectral sensitivity of the silver halide emulsions contiguous thereto.

A wide variety of colorless hydroquinone derivatives may be utilized in the dye developer diffusion transfer systems of the invention as auxiliary silver halide developing agents. Such colorless hydroquinone derivatives are substantially insoluble in Water and diffusible in the hydrophilic organic colloids comprising the present photographic elements in the presence of alkaline processing compositions. Typical suitable colorless hydroquinone derivatives are listed in columns 7 and 8 of US. Patent 3,146,102 and are preferably employed in one or more layers of the light-sensitive element used in the present process. A preferred auxiliary developing agent is 4-methylphenylhydroquinone.

A wide variety of diifusible onium compounds may also be utilized in the dye developer systems of the present invention. Such onium compounds, that is, compounds that contain an organic cation, are diffusible in the hydrophilic organic colloids comprising the present photographic elements in the presence of alkaline processing compositions. Such onium compounds are typically quaternary ammonium compounds, quaternary phosphonium compounds or tertiary sulfonium compounds. A particularly useful class of onium compounds are the heterocyclic quaternary ammonium compounds that are capable of forming diffusible methylene bases in alkaline processing compositions such as those described in U.S. Patent 3,146,102. The onium compounds are preferably utilized in the alkaline processing composition, although the onium compounds may also be utilized in the reception sheet, or less desirably, in one or more layers of the light-sensitive element, or in at least two of such positions.

Water-soluble silver halide solvents may be employed in the alkaline processing compositions used in the dye developer transfer process of the invention, particularly in conjunction with onium compounds and colorless hydroquinone derivatives as described above, such addenda lending further improvement in color quality results. Preferred silver halids solvents are thiosulfates such as sodium, potassium and ammonium thiosulfate.

The silver halide emulsions utilized in preparing photographic or light-sensitive elements used in the present diffusion transfer systems may be any of the conventional negative-type, developing-out emulsions. Typical suitable silver halides include silver chloride, silver bromide, silver bromoiodide, silver chloroiodide, silver chlorobromoiodide and the like. Mixtures of more than one of such silver halides can also be utilized. In accordance with usual practice, such silver halide emulsions can contain spectral sensitizers, speed-increasing addenda, hardeners, coating aids, plasticizers, antifoggants and the like conventional emulsion addenda.

In preparing the silver halide emulsions, as well as in preparing the various layers of photographic elements used in the present diffusion transfer process, including the layers containing the dye developers and colorless hydroquinone derivatives, mordant-containing reception layers, interlayers, topcoat layers and the like, a Wide variety of hydrophilic organic colloids can be utilized as the vehicle or carrier. Gelatin is preferably used as the hydrophilic colloid or carrier material although such material as polyvinyl alcohol and its water-soluble derivatives and copolymers, Water-soluble copolymers such as polyacrylamide, imidized polyacrylamide, etc., and other water-soluble film-forming materials that form water-permeable coats such as colloidal albumin, water-soluble cellulose derivatives, etc., may be utilized in preparing the photographic elements. Compatible mixtures of two or more of such colloids can also be utilized.

The various layers utilized in preparing the diffusion transfer photographic elements may be coated on a wide variety of photographic supports. Typical supports include cellulose nitrate film, cellulose acetate film, polyvinyl acetal film, polystyrene film, paper, polyethylenecoated paper, polypropylene-coated paper, glass and the like.

Similarly, a wide variety of receiving sheets may be utilized to receive the transfer images from the photographic elements. Typical reception layers for receiving sheets include such materials as linear polyamides, proteins such as gelatin, polyvinyl pyrrolidones, poly-4-vinyl pyridine, polyvinyl alcohol, polyvinyl salicylal, partially hydrolyzed polyvinyl acetate, methyl celluose, regenerated cellulose, or mixtures of such. The reception layers may be coated on a suitable support of the type described above for the light-sensitive elements of the invention and including transparent as Well as opaque supports.

Receiving sheets that release acidic material such as that derived from an acidic polymer or other acidic compound at a controlled rate as are described in US. Patent 2,584,030 are particularly useful. Such acidic materials are typically positioned in layers on the receiving sheet below the dye developer reception layer, there suitably being a spacer layer between the acid layer and the mordanting layer to control the releasing of acidic material. Such acidic materials serve to neutralize residual portions of the alkaline activator on the receiving sheet.

A wide variety of nondilfusible cationic or basic dyemordanting compounds can be used in liquid permeable reception layers including amines such as polymeric amines, quaternary ammonium compounds, quaternary phosphonium compounds and tertiary sulfonium compounds. Such mordants are nondiffusible in the alkaline processing composition and contain at least one hydrophobic ballast group. As described above, either or both of the onium compounds and colorless hydroquinones can be incorporated on the receiving sheets. The receiving sheets may also contain development arrestors such as mercaptoazoles and iodides.

Light-sensitive elements containing integral reception layers for dye developer images may also be utilized. Such integral reception layers can be coated beneath the emulsion and dye developer layers near the support. A stripping layer coated over the integral reception layer can be used to facilitate the removal of the overcoated layers after the diffusion of the dye developer images to the reception layer.

The processing compositions or activators used to initiate development of the exposed light-sensitive elements are strongly alkaline. Such processing compositions generally have a pH of at least 12 or contain at least .01 N hydroxyl ion. Alkali metal hydroxides, such as sodium hydroxide, and sodium carbonate, are advantageously used in the composition for imparting such high alkalinity. However, volatile amines such as diethyl amine can also be used, such amines having the advantage of being volatilized from the prints to leave no residue of alkali.

Due to the unstable character of the hydroquinone derivatives in strong alkali, the colorless hydroquinone derivatives are preferably not used in the processing composition although when the pyridinium salts are present improved results are obtained. Such processing compositions are generally aqueous liquids or solutions, and when utilized in rupturable pods for in-camera processing such as described in U.S. Patent 2,435,717, generally contain thickening agents such as hydroxyethyl cellulose or carboxymethyl cellulose. T hickened processing compositions typically have viscosities of at least 5,000 cps. to 100,000 or even 200,00 cps.

The following nonlimiting examples will illustrate the invention.

EXAMPLE 1 A yellow dye developer precursor is prepared in the following manner. Twenty grams of 4-acetamidophenethylbenzoquinone are dissolved in 200 milliliters of dry methanol which contains 10 grams of freshly fused zinc chloride and the mixture is refluxed for a period of four hours. The solution is cooled overnight and is filtered to yield 3 grams of the yellow dye developer precursor, 2- (4'-acetamidophenethyl -5-methoxybenzo quinone.

To increase the yield of the precursor, 20 grams of silver oxide are added to the filtrate and the solution is refluxed for a period of four hours. It is then filtered while hot and allowed to cool. The filtration yielded another 2.5 grams of the S-methoxyquinone.

The following example illustrates the production of a yellow dye developer of the present invention.

EXAMPLE 2 Sixteen grams of the S-methoxyquinone that are produced according to the procedure of Example 1 are bydrogenated in ethanol over a palladium on carbon catalyst until no further uptake of hydrogen is observed. The

solution is evaporated to dryness and is treated with 50 OCOCHs l-ornom-Qmroo on,

CHaO

l OCOCH having a melting point of 162 "-163 C.

Next, 15 grams of the diacetate are dissolved in 300 milliliters of methanol saturated with hydrochloric acid and refluxed for one hour. The solution is evaporated to dryness and the residue contains the compound 8 2- (4'-an1inophenethyl)-5-methoxyhydroquinone hydrochloride cmom-Qrrmnor CHaO I OH

Nine and one-half grams of the aniline hydrochloride in the form of the residue thereof are dissolved in 50 milliliters of acetic acid which is saturated with hydrogen chloride. Fifty milliliters of acetyl chloride are added to the solution while stirring and passage of hydrogen chloride therethrough.

The mixture is warmed at a temperature of 40 C. for; a period of one hour. The mixture is then cooled and diluted with ether. The product separates upon scratching and an 11.5 gram yield of the following compound is realized.

4- [2',5'-diacetoxy-4'-methoxyphenethyl] aniline hydrochloride (I) COCH:

COCHa The amine hydrochloride in an amount of 11.5 grams is suspended in milliliters of water and 6 milliliters of concentrated hydrochloric acid are added. The suspension is cooled to a temperature of 5 C. and is treated dropwise with a solution composed of 2 grams of sodium nitrite in 15 milliliters of water. After stirring for a period of one hour, the resulting diazotized amine solution is added with stirring to a mixture of 7 grams of l phenyl 3 N n hexylcarboxamido 5 pyrazolone which is dissolved in a solution composed of 230 milliliters of acetone, 40 milliliters of pyridine, and 100 milliliters of a'saturated sodium bicarbonate solution.

The temperature during the addition is maintained at about 10 C. After about one hour, the product is filtered off and recrystallized from isopropyl alcohol. A yield of, 12 grams of the following compound having a melting point of 157 to 159 C. is realized.

4- [p- (2',5'-diacetoxy-4'-methoxyphenethyl)phenylazo] -1- phenyl-3-N-n-hexylcarboxamido-S-pyrazolone Thirty-five grams of the diacetate are dissolved in one liter of dimethylsulfoxide and the solution is heated to a temperature of 40 C. under nitrogen. Next, 350 milliters of a 10 percent sodium hydroxide solution are added to the solution and the temperature is maintained below 50 C. After 10 minutes the solution is cooled to room temperature and 100 milliters of concentrated hydrochloric acid are added.

The mixture is poured into 2.5 liters of a 5 percent dilute hydrochloric acid solution while stirring. The product is filtered off and is recrystallized from 2-ethoxyethanol and has a melting point of 198-200 C. A yield of 19 grams of the following dye developer is realized.

9 4- [p- 2',5 '-dihydroxy-4-methoxyphenethyl phenylazo] -1- phenyl-3 -N-n-hexylcarboxamido-S-pyrazolone CHaO The product has an absorption max A of 450 nm. when tested in acetone.

The following comparative examples illustrate the employment of the dye developers of the invention in due developer dilfusion transfer systems.

EXAMPLE 3 A photosensitive element is prepared by coating a cellulose acetate film support with suitably hardened gelatln layers as follows:

(1) Gelatin subbing layer The cellulose acetate film support is coated with 908 milligrams per square foot of gelatin to provide a subbing layer.

( 2) Yellow dye developer layer (3) Blue-sensitive emulsion layer A blue-sensitive silver bromoiodide emulsion is coated onto the yellow dye developer layer in an amount suflicient to provide 69 milligrams of silver per square foot.

(4) Overcoat layer A final gelatin emulsion overcoat layer is spread over the blue-sensitive layer so as to provide a coverage of 32 milligrams of the gelatin per square foot.

A sample of the freshly coated film is exposed in an Eastman 1B Sensitometer 1/10 to a SOD-watt positive lamp plus a 4.08 Corning filter and is processed with a processing solution disposed in a rupturable processing pod and having the composition set forth in Table 1 below:

TABLE 1 Percent Hydroxyethyl cellulose (Hercules type 250 high viscosity) 2.0 Sodium hydroxide 5.7 Sodium thiosulfate pentahydrate 0.4 Benzotriazole 2.4 l-benzyl-u-picolinium bromide 2.4

During the processing, the photosensitive element is maintained in contact with a color receiving sheet at a gap of 0.0044 inch. The receiving sheet is a layered element which has been prepared by coating a cellulose acetate butyrate subbed paper support successively with the following layers:

(a) A polymeric acid layer, such as a copolymer formed of butyl acrylate and acrylic acid, for pH control;

(b) A polyvinyl alcohol spacer layer;

(c) A dye mordant layer comprising poly-4-vinyl pyridine and polyvinyl alcohol; and

(d) A protective overcoat layer of polyvinyl alcohol.

The photosensitive negative is stripped from the receiving sheet. The film speed of the blue sensitive element containing the conventional yellow dye developer is measured and recorded for control purposes.

EXAMPLE 4 The procedure of Example 3 is repeated except that the auxiliary developer, 4-methylphenylhydroquinone, is included in the gelatin overcoat layer at a coverage of 20 milligrams of auxiliary developer per square foot of surface.

The film speed of the blue sensitive element is again tested. The result is shown in Table 2.

EXAMPLE 5 The procedure of Example 3 is repeated, with the exception that the novel yellow dye developer, 4[p-(2,5'- dihydroxy-4' methoxyphenethyl)phenylazo]-1-phenyl-3- N-n-hexylcarboxamido-S-pyrazolone, is substituted for the dye developer previously employed in the yellow dye developer layer (2) at a coverage of 55 milligrams per square foot. The film speed of the blue sensitive element is again measured and is set forth in Table 2, below.

EXAMPLE 6 The procedure of the previous example is repeated, except that 20 milligrams per square foot of the auxiliary silver halide developer, 4'-methylphenylhydroquinone, (4'-MPHO) are included in the gelatin overcoat layer (4).

The comparative film speeds which are measured in Examples 3 to 6 are set forth below:

TABLE 2 A ili t g 1? B Ileed ux ary a e 0 Example No. Dye Developer Developer Dmax w 3 Unsubstituted None Control. 4 .do 4-MPHQ, +0.13 5 5-methoxy substituted None +0.65 6 do 4-MPHQ +0.60

As seen from a comparison of the results set forth in Table 2, a tremendous speed advantage is provided by the employment of the 5-methoxy substituted dye developers of the present invention.

The following examples illustrate the employment of the novel dye developer of the invention in multilayered, multicolor dye developer dilfusion transfer systems.

EXAMPLES 7-8 A multilayer, multicolor sensitive element is prepared by coating a film support comprising cellulose acetate with suitably hardened gelatin layers as follows:

(1) Cyan dye developer layer An aqueous gelatin containing the cyan dye developer 5,8 dihydroxy-l,4-bis[(B-hydroquinonyl-a-methyl)ethylamino] anthraquinone is dissolved in a mixture of N-nbutylacetanilide, 4-methyl cyclohexanone and dispersing agent Alkanol B. The mixture is passed through a colloid mill several times, coated on the subbed support so as to provide 146 milligrams per square foot of the dye developer and 221 milligrams per square foot gelatin. The coating is dried so as to volatilize the 4-methyl cyclohexanone.

(2) Red-sensitive emulsion layer A gelatino silver bromoiodide emulsion layer, which is sensitized to the red region of the spectrum is spread upon the cyan dye developer layer to provide a coverage of 219 milligrams of silver and 86 milligrams of gelatin per square foot.

1 1 (3) Interlayer A sodium alginate interlayer is then spread on the redsensitive emulsion layer at a coverage of 27 milligrams per square foot.

(4) Magenta dye developer layer An aqueous gelatin solution containing the magenta dye developer 2 [p (2,5 dihydroxyphenethyl) phenylazo]-4-n-propoxy-l-naphthol and calcium chloride is dissolved in a mixture of cyclohexanone, N-n-butylacetanilide and Alkanol B is passed through a colloid mill several times, coated on the interlayer and dried to volatilize the cyclohexanone. A concentration of 55 milligrams of the magenta dye developer, 20.5 milligrams of the calcium chloride and 74 milligrams of gelatin per square foot coverage is provided.

(5) Green-Sensitive Emulsion Layer A green-sensitive silver bromoiodide emulsion is coated on the magenta layer at a coverage of 103 milligrams of silver and 62 milligrams of gelatin per square foot.

(6) Interlayer A gelatin interlayer containing the yellow filter dye, benzidine yellow, and the auxiliary developer 4'-methylphenylhydroquinone is spread onto the green-sensitive emulsion layer at a concentration of 140 milligrams of gelatin, 50 milligrams of the benzidine yellow and 8 milligrams of the hydroquinone per square foot.

(7) Yellow dye developer layer An aqueous gelatin solution of the yellow dye developer, 1 phenyl 3 N n hexylcarboxamido 4 [p 2',5 dihydroxy 4 methoxyphenylethyl)-phenylazo]- S-pyrazolone, is dissolved in a mixture of ditetrahydrofurfuryl adipate, ethylene glycol monobenzyl ether, and Alkanol B, is passed through a colloid mill several times. The resulting dispersion is chilled to set it, washed to remove ethylene glycol monobenzyl ether followed by coating upon the interlayer and drying. A coverage of 55 milligrams of the yellow dye developer and 96 milligrams of gelatin per square foot is provided.

(8) Blue-sensitive emulsion layer A blue-sensitive silver bromoiodide emulsion is spread onto the yellow dye developer layer at a coverage of 55 milligrams of silver per square foot and 50 milligrams of gelatin per square foot.

(9) Overcoat layer TABLE 3 Percent by weight Hydroxyethyl cellulose (HEC) 2.0 Sodium hydroxide 5.7 Sodium thisoulfate pentahydrate 0.4 Benzotriazole 2.4 1-benzyl-2-picolinium bromide 2.4

The exposed film is processed at a gap of 0.0044 inch (corresponding to the thickness of the activator layer) for a period of 60 seconds in contact with a color receiving sheet. The receiving sheet is a cellulose acetate butyrate subbed paper support carrying in the following order.

(1) A polymeric acid layer for pH control, (2) A polyvinyl alcohol spacer layer,

TABLE 4 Relative Speed (0.3 below Dmax) Example No. Dye Developer Blue Green Red 7 5-methoxysubstituted 251 166 112 8 Unsubstituted 100 100 As seen from the foregoing results, the incorporation of the S-methoxysubstituted dye developer of the present invention into the multilayer, multicolor diffusion transfer element provides a substantial increase in film speed over that which can be realized with the conventional yellow dye developer.

The invention has been described in considerable detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

We claim:

1. A photosensitive material which comprises a lightsensitive silver halide emulsion and a 5-[lower]alkoxyhydroquinone yellow dye developer contiguous to the silver halide of said emulsion.

2. The photosensitive material of claim 1 wherein the dye developer has the formula wherein R represents a lower alkyl group and X represents a yellow image-producing chromophore moiety.

3. The photosensitive material of claim 2 wherein X is the moiety represented by the group wherein R represents an alkylene group of from 1 to 5 carbon atoms; Ar represents an aryl group; Z represents a member selected from the group consisting of lower alkyl, lower alkoxy and halogen; m is an integer of from 0 to 2; and, Q represents a 5-pyrazolone group attached, at the 4-carbon atom thereof, to the azo group.

4. The photosensitive material of claim 3, wherein the dye developer has the structural formula 5. In a photographic product composed of a photosensitive element comprising at least one light sensitive silver halide emulsion layer and a dye developer which is both a silver halide developing agent and a dye, contiguous to the silver halide of said silver halide emulsion layer; and, a dye developer reception layer; said photosensitive element and said dye developer reception layer being capable of being superposed on each other; the improvement which comprises using a -[lower]-alkoxyhydroquinone as yellow dye developer.

6. The product of claim 5 wherein the yellow dye de veloper has the formula at the 4-carbon atom thereof, to the azo group.

8. The product of claim 7 wherein the yellow dye developer has the structural formula C ONHCaHrs 9. A process for producing a photographic transfer image which comprises processing an exposed photosensitive element comprising at least one light-sensitive silver halide emulsion layer and a 5-(lower)alkoxyhydroquinone as a yellow dye developer contiguous to the silver halide of said silver halide emulsion layer, said processing being effected by treating said photographic element with an alkaline solution, developing a latent image in the regions of exposure of said silver halide layer and thereby immobilizing said dye developer in said regions of exposure, dye developer in undeveloped regions diffusing imagewise in register to a dye developer reception layer.

10. The process of claim 9 wherein the yellow dye developer has the formula wherein R represents a lower alkyl group and X represents a yellow image-producing chromophore moiety.

11. The process of claim 10 wherein X is the moiety represented by the group wherein R represents an alkylene group of from 1 to 5 carbon atoms; Ar represents an aryl group; Z represents a member selected from the group consisting of lower alkyl, lower alkoxy and halogen; m is an integer of from O to 2; and, Q represents a S-pyrazolone group attached, at the 4-carbon atom thereof, to the azo group.

12. The process of claim 11 wherein the yellow dye developer has the structural formula ICHzCH2- N=N-||CONHOaH1a CH 0- N AH U References Cited UNITED STATES PATENTS 3,134,672 5/1964 Blout et al. 9629 3,141,772 7/1964 Green 9629 NORMAN G. TORCHIN, Primary Examiner A. T. SURO PICO, Assistant Examiner US Cl. X.R. 963, 77 

